Fatemeh Behjat - English Department, Islamic Azad University, Abadeh Branch, Abadeh

Considering multilingualism as a subcategory of second language acquisition, the present paper aimed at finding out whether knowing two or three languages could help the improvement of the grammar performance of Iranian EFL learners. For this purpose, three groups of participants, the first knowing only Persian as their mother tongue, the second, Persian and French, and the third, Persian, French and German were taken under investigation at Tehran Kish-Air Institute and Shiraz Islamic Azad University, Iran. After the three groups’ knowledge of Persian, and the knowledge of French in the last two groups was proved to be at the same level, the participants took an English grammar test as the pre- and post-test. English Grammar instruction took place for about three months. The comparison of all three groups’ grammar performance revealed that those who knew second and third languages could outperform the participants who did not know a foreign language. The results also showed that there was no significant difference between the performance of those who knew Persian and French and those who knew French, Persian and German

English grammar performance, EFL learners, language acquisition, multilingualism